Just an idea about the vest, you can change them if you want, but i can't force you. :U
I'm honestly not thinking this will make it into the final, as it is not too realistic, but here goes.
Vests
Recon, a lightweight vest that had added communication (???) Cannot take a lot of damage before being destroyed.
Police, another lightweight vest, protects well against pistols and low caliber SMG's. Can take a good bit of damage.
Military, a heavy vest w/ a helmet, protects against assault rifles (and maybe dmr's.)
Stockpiler, a medium-weight vest, has space for extra magazines.
Medic, a med-weight vest that allowed medical supplies to heal twice as much health and also allows giving teammates health.
Flak Jacket, a heavy vest which can take a lethal explosion before being destroyed. (isn't too good at bullets though.
Having a lightweight vest lowered the player's move speed to approx. 90%, A medium-weight vest would lower it to 80%, a heavy vest lowers move speed to 75%.
The police vest cannot protect against higher caliber rounds, and the military vest isn't made to take pistol bullets (to balance it out,) but they both offer the same resistance to damage as other vests when stuck by projectiles outside their intended protection range (i'm thinking 15%).